青藏高原东部若尔盖盆地全新世野火活动与气候变化的关系  

Relationship between Holocene wildfire activities and climate change in the ZoîgéBasin,eastern Qinghai-Xizang Plateau

作　　者：潘元琪 查小春 黄春长 庞奖励 周亚利 张睿玺 赵晓康 王娜 白鑫 PAN Yuanqi;ZHA Xiaochun;HUANG Chunchang;PANG Jiangli;ZHOU Yali;ZHANG Ruixi;ZHAO Xiaokang;WANG Na;BAI Xin(School of Geography and Tourism,Shaanxi Normal University,Xi’an 710119,China)

机构地区：[1]陕西师范大学地理科学与旅游学院,陕西西安710119

出　　处：《冰川冻土》2025年第1期255-266,共12页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41971116,42271046);陕西师范大学博士自由探索项目(2020TS102)资助。

摘　　要：通过实地考察,选取青藏高原东部若尔盖盆地的一个沉积序列完整的全新世沉积剖面,提取炭屑、磁化率和总有机碳等气候代用指标,重建了该地区全新世野火和气候变化的历史,揭示了区域内全新世古环境与野火变化之间的关系。研究表明:在整个全新世时期,若尔盖盆地野火活动主要为区域性野火,且区域野火以燃烧木本植物为主,局地野火以燃烧草本植物为主。全新世早期(8.5 ka之前),虽然温度有所回升,但是依然干冷,沙尘暴频繁,地表堆积形成了风成沙层,有限的植物生物量限制了野火活动的发生,区域野火和局地野火发生频率均较低;全新世中期(8.5 ka至3.1 ka),在暖湿的气候背景下,古土壤层发育形成,温度的升高和降水的增加使若尔盖盆地的植物生物量增多,与植物生物量增加有关的区域野火和局地野火事件频繁发生;气候凉干的全新世晚期(3.1 ka之后),现代草甸土堆积而成,野火活动总体减弱,全新世晚期植物生物量下降可能是区域野火活动减少的原因,但此阶段局地野火的加剧也可能是受人类活动的影响所致。本文研究结果有助于深入了解若尔盖盆地野火历史和气候演变过程。Wildfire activities,an important part of natural ecosystems,are strongly influenced by climate change and vegetation types.As one of the best proxies for reconstructing wildfire history and wildfire occurrence mechanisms,the quantitative statistics and morphological analysis of charcoal can not only recover the frequency,intensity and changes of wildfire activities over geologic historical periods,but also understand the types of vegetation(woody and herbaceous plants)in which wildfires occurred.In addition,different sizes of charcoal can reflect the distance between the wildfire site and the depositional area. The Qinghai-Xizang Plateauwith its high-altitude is very sensitive to the environment changes. However, there are few reliable charcoal records in the Qinghai-Xizang Plateau, and the research results mainly focused on macroscopic charcoal anatomyand the charcoal records in the late Holocene archaeological sites. In this study, a Holocene sedimentary profilewith the complete sedimentary sequences was founded in the Zoîgé Basin on the eastern Qinghai-Xizang Plateauthrough extensive field investigations. The history of Holocene wildfire activities and climate changes in theZoîgé Basin were reconstructed using a variety of paleoclimate proxies (charcoal, magnetic susceptibility and total organic carbon), and the relationship between Holocene environment change and wildfire activities was revealed. The results showed that the wildfire activities in the Zoîgé Basin were dominated by regional wildfire activities during the Holocene, and local wildfire activities were dominated by burning woody plants, regionalwildfire activities were dominated by burning herbaceous plants. However, the low magnetic susceptibility (mean7. 9×10-8 m3/kg) and TOC (mean 0. 23%) of the aeolian sand layer in the early Holocene (before 8. 5 ka) werepresented indicated that the temperature has increased, but the climate was still dry and cold, with frequent duststorms and weak biopedogenesis. The lowest value of total charcoal conc

关 键 词：炭屑 野火 古环境 全新世 若尔盖盆地 

分 类 号：P534.632[天文地球—第四纪地质学]